1. Field of the Invention
The present invention relates to a shock absorber, and more particularly, to a piston assembly of a shock absorber.
2. Description of the Related Art
Generally, a shock absorber is designed to support a weight of a vehicle body and suppress and dampen a vibration transferred from a road surface to the vehicle body, contributing to improving a ride comfort and protecting loaded goods and various parts of a vehicle.
Such a shock absorber includes a cylinder filled with a working fluid (oil), a reciprocating piston rod connected to a vehicle body, and a piston valve connected to a lower end of the piston rod to slide within the cylinder and control a flow of the working fluid.
During a compression stroke of the shock absorber, oil of a compression chamber disposed under the piston valve moves to a rebound chamber through a compression passage formed in the piston valve.
During a rebound stroke of the shock absorber, oil of a rebound chamber disposed over the piston valve moves to a compression chamber through a rebound passage formed in the piston valve to thereby absorb a vibration and shock.
In the piston valve, the use of a sandwich type piston increasing the degree of freedom of tuning has recently been growing.
The sandwich type structure tends to make the inner passage of the piston complicated. Therefore, unit price is increased and the productivity is lowered.